Present ocean acidification rates are unprecedented: research

March 1, 2012

The single-celled organism Stensioeina beccariiformis survived the asteroid impact that killed the dinosaurs 65 million years ago but went extinct nine million years later, when the oceans acidified due to a massive CO2 release. It ranged across many depths, in all oceans. Credit: Ellen Thomas

The world's oceans may be turning acidic faster today from human carbon emissions than they did during four major extinctions in the last 300 million years, when natural pulses of carbon sent global temperatures soaring, says a new study in Science. The study is the first of its kind to survey the geologic record for evidence of ocean acidification over this vast time period.

"What we're doing today really stands out," said lead author Bärbel Hönisch, a paleoceanographer at Columbia University's Lamont-Doherty Earth Observatory. "We know that life during past ocean acidification events was not wiped outnew species evolved to replace those that died off. But if industrial carbon emissions continue at the current pace, we may lose organisms we care aboutcoral reefs, oysters, salmon."

The oceans act like a sponge to draw down excess carbon dioxide from the air; the gas reacts with seawater to form carbonic acid, which over time is neutralized by fossil carbonate shells on the seafloor. But if CO2 goes into the oceans too quickly, it can deplete the carbonate ions that corals, mollusks and some plankton need for reef and shell-building.

That is what is happening now. In a review of hundreds of paleoceanographic studies, a team of researchers from five countries found evidence for only one period in the last 300 million years when the oceans changed even remotely as fast as today: the Paleocene-Eocene Thermal Maximum, or PETM, some 56 million years ago. In the early 1990s, scientists extracting sediments from the seafloor off Antarctica found a layer of mud from this period wedged between thick deposits of white plankton fossils. In a span of about 5,000 years, they estimated, a mysterious surge of carbon doubled atmospheric concentrations, pushed average global temperatures up by about 6 degrees C, and dramatically changed the ecological landscape.

The result: carbonate plankton shells littering the seafloor dissolved, leaving the brown layer of mud. As many as half of all species of benthic foraminifers, a group of single-celled organisms that live at the ocean bottom, went extinct, suggesting that organisms higher in the food chain may have also disappeared, said study co-author Ellen Thomas, a paleoceanographer at Yale University who was on that pivotal Antarctic cruise. "It's really unusual that you lose more than 5 to 10 percent of species over less than 20,000 years," she said. "It's usually on the order of a few percent over a million years." During this time, scientists estimate, ocean pHa measure of acidity--may have fallen as much as 0.45 units. (As pH falls, acidity rises.)

Ellen Thomas, a paleoceanographer at Yale University, examines a core of sediment from some 56 million years ago, when the oceans underwent acidification that could be an analog to ocean changes today. Credit: Steve Schellenberg

In the last hundred years, atmospheric CO2 has risen about 30 percent, to 393 parts per million, and ocean pH has fallen by 0.1 unit, to 8.1--an acidification rate at least 10 times faster than 56 million years ago, says Hönisch. The Intergovernmental Panel on Climate Change predicts that pH may fall another 0.3 units by the end of the century, to 7.8, raising the possibility that we may soon see ocean changes similar to those observed during the PETM.

More catastrophic events have shaken earth before, but perhaps not as quickly. The study finds two other times of potential ocean acidification: the extinctions triggered by massive volcanism at the end of the Permian and Triassic eras, about 252 million and 201 million years ago respectively. But the authors caution that the timing and chemical changes of these events is less certain. Because most ocean sediments older than 180 million years have been recycled back into the deep earth, scientists have fewer records to work with.

During the end of the Permian, about 252 million years ago, massive volcanic eruptions in present-day Russia led to a rise in atmospheric carbon, and the extinction of 96 percent of marine life. Scientists have found evidence for ocean dead zones and the survival of organisms able to withstand carbonate-poor seawater and high blood-carbon levels, but so far they have been unable to reconstruct changes in ocean pH or carbonate.

At the end of the Triassic, about 201 million years ago, a second burst of mass volcanism doubled atmospheric carbon. Coral reefs collapsed and many sea creatures vanished. Noting that tropical species fared the worst, some scientists question if global warming rather than ocean acidification was the main killer at this time.

The effects of ocean acidification today are overshadowed for now by other problems, ranging from sewage pollution and hotter summer temperatures that threaten corals with disease and bleaching. However, scientists trying to isolate the effects of acidic water in the lab have shown that lower pH levels can harm a range of marine life, from reef and shell-building organisms to the tiny snails favored by salmon. In a recent study, scientists from Stony Brook University found that the larvae of bay scallops and hard clams grow best at pre-industrial pH levels, while their shells corrode at the levels projected for 2100. Off the U.S. Pacific Northwest, the death of oyster larvae has recently been linked to the upwelling of acidic water there.

Lab studies show that clownfish in acidified waters can lose their ability to sniff out predators and find their way home. (Metatron)

In parts of the ocean acidified by underwater volcanoes venting carbon dioxide, scientists have seen alarming signs of what the oceans could be like by 2100. In a 2011 study of coral reefs off Papua New Guinea, scientists writing in the journal Nature Climate Change found that when pH dropped to 7.8, reef diversity declined by as much as 40 percent. Other studies have found that clownfish larvae raised in the lab lose their ability to sniff out predators and find their way home when pH drops below 7.8.

"It's not a problem that can be quickly reversed," said Christopher Langdon, a biological oceanographer at the University of Miami who co-authored the study on Papua New Guinea reefs. "Once a species goes extinct it's gone forever. We're playing a very dangerous game."

It may take decades before ocean acidification's effect on marine life shows itself. Until then, the past is a good way to foresee the future, says Richard Feely, an oceanographer at the National Oceanic and Atmospheric Administration who was not involved in the study. "These studies give you a sense of the timing involved in past ocean acidification eventsthey did not happen quickly," he said. "The decisions we make over the next few decades could have significant implications on a geologic timescale."

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43 comments

What decisions are we going to make EXACTLY? Stop driving cars? Nuke China to prevent them from operating their coal plants or building more? Shut off our grid and let 180 million people die and live like 18th century serfs?

What is your plan that will ACTUALLY have some slim chance of implementation in the face of the REAL WORLD, and the REAL political situation?

It is getting harder and harder to believe all the things that CO2 has caused and will cause.

Are you just joking? Have you ever had a chemistry course (to understand pH changes)? Have you ever had a heat transfer course to understand the role of CO2 in trapping long-wavelength electromagnetic radiation? Either this is a joke or you don't have a scientific background. To deny the evidence that CO2 is a pollutant that does not just make the weather in Canada and Alaska better and increases crop growth (spatially limited) is to show you can't have a good scientific background. You learn about acidification in the first year of chemistry. You learn about active gases (those with vibrational, bending, and rotational resonances in the Solar spectrum and the spectrum of flames) in a first course in Radiant Heat Transfer. I have to assume you have never taken those or you flunked out.

@thermodymaics Your belligerent superior attempt a communication is a perfect example of why "Big Green" is losing this debate. Remember we live in a democracy where the majority are scientifically illiterate. Your obvious lack of intelligence in this regard is not going to convince anyone that the science trained are actually smart. With friends like you who needs enemies?

How long does CO2 hold onto a "trapped" longwave photon? Where does it go after that?

It gets radiated away in a random direction, often getting re-absorbed by an adjacent CO2 molecule.

It does NOT.

It collides with another atmospheric molecule within 0.00000000015 seconds. The energy represented by an absorbed photon gets thermalized in the atmosphere at a much faster rate than the relaxation time of an excited CO2 molecule.

The Ocean absorbs 0.5% of the excess CO2 in the atmosphere above the equilibrium level of 270 ppm each year. That currently translates into about 2 gigatonnes Carbon per year (but it was only 1 gigatonne just 50 years ago).

There are around 14,000 gigatonnes Carbon in the ocean so, 2 per year is not going to make much difference. In the PETM, when volcanoes released something like 2500 gigatonnes of Carbon, that might have made a difference (given the Ocean would be absorbing 0.5% of the excess).

Ziphead: Or people don't get "what they deserve", and this era fear will be ridiculed in the future. As an era when even more rational people succumb to alarmist mentality. All I see is AGW propaganda everywhere. Last I've seen musical version on TED (yesterday), they're still talking about anti-AGW propaganda, but I always see just AGW one, sorry (and also anti-GW, which is just plain stupid, because GW is a fact, but this is not anti-AGW). I recognized the typical mixture of lie and truth in their sentences. A typical sentence: Some awful GW effect will occur - which is caused by human CO2 emissions. So first we have some observed GW evidence, and then some unsupported claim is appended as a explanation. Classics. I'm all for investing the money to solve the root of the problem, instead of trying to implement costly limits on CO2. Also of course, the AGW movement is trying to bypass the democratic principles by fear only, that alone is evidence enough.

It gets radiated away in a random direction, often getting re-absorbed by an adjacent CO2 molecule.

not bloody likely... 390 parts per million by volumeThe density of air at sea level is about 1.2 kg/m3 (1.2 g/L)

now, i wont bore a genius like you with math, but out of that volume about 757mg/m3 is Co2thats 10358223131106566689388 molecules per cubic meter.the molecules, being in air, have a mean free path of about 93nmhowever, you pretend the other molecules are not present to figure the mean free path of infrared light which the other molecules dont absorb (except water).

so... since i laid the groundwork, why dont you tell me how many collisions light moving at 299,792,458 m/s would make..

Lets look at the evidence shall we ... there is a layer of mud without plankton shells. Fair enough. There was warming at the time which caused CO2 to increase in the atmosphere (remember in observable geo-science warming causes CO2 with an 800 year lag, not the other way around). So whats the evidence that one caused the other except for temporal coincidence?Key question is, what was pH before the period, what was CO2, what was pH and CO2 after, are they correlated, and is the pH sufficiently high to cause carbonate to dissolve. None of that is addressed in this alarmist propoganda piece.

I'm sorry to burst your bubble Stargazer, but ocean acidification is a happening with horrific consequences to the bleached coral reefs. The shallower the water, and the warmer the water, the faster the acid eats away calcium including vital proto-planktons and diatoms.

You know, if you really read up on the subject, you would find that it doesn't take much in PH change to really upset the whole balance of an eco-system. Massive fish kills will be your fault.

That is what is happening now. In a review of hundreds of paleoceanographic studies, a team of researchers from five countries found evidence for only one period in the last 300 million years when the oceans changed even remotely as fast as today

Now what part of that do you not understand? The period that was faster than today was 54 million years ago, and no one wants a repeat of that. Yea, I can here you say "Yeah bring it on" like the fool you are.

[quote]Have you ever had a heat transfer course to understand the role of CO2 in trapping long-wavelength electromagnetic radiation?[/quote]

Nah... At Bronx Science we did physics the old way, with our heads... :) and we understood it better...

(before you disparage, realize its a high school with 7 Nobel prizes-more six have won Pulitzer Prizes)

What, exactly, do you want interpreted from this. Are you saying that 7 Nobel winners had only a high-school education? Are you saying that they did not learn anything in college to help them produce their innovations?

Ziphead: Or people don't get "what they deserve", and this era fear will be ridiculed in the future...

I am sorry to have spoiled your day with trivial observation, sir. How about: "yes, we can have 10 billion on the planet driving around in their 4WDs, getting ever so fatter on five dollar burgers from here into eternity"... or shall I just say: "yes we can".

Ziphead: Or people don't get "what they deserve", and this era fear will be ridiculed in the future...

I am sorry to have spoiled your day with trivial observation, sir. How about: "yes, we can have 10 billion on the planet driving around in their 4WDs, getting ever so fatter on five dollar burgers from here into eternity"... or shall I just say: "yes we can".

"What is your plan that will ACTUALLY have some slim chance of implementation" Awesome question mystik - take a look at this video to see that there are proposals out there that can and will make a difference. http://www.youtub...VlZ9v_0o Check out greening the desert - http://www.youtub...pjOG4pXI These solutions just show my bias - but we could look at thorium reactors - etc. etc. The point I feel we are stuck on at the moment is the anti science lobby that we see repeatedly on this board - deflecting the dialogue away from the solutions - and constantly attacking the science that is attempting to help us understand - and move forward.

Ziphead: You're changing the subject. Those are different questions. This is another piece of AGW reasoning. Trying to prove that AGW is right, because people are behaving in such and such way, and they deserve it. Therefore the AGW is correct, because it's is a punishment for not thinking ecologically. THIS is just insulting general logic! All I need, is a scientific paper on a link between GW and human cause.. there are of course plenty of those. But also this paper mustn´t be shredded by peer review to bits. I don't need Gore's movies, musicals, songs, allegoric vehicles, and other magicians using their tricks to invoke a fear to try to overload my logic reasoning. I'm that type of person that needs peer reviewed evidence by people from that area of expertise, and not these fabulations by the comedians and sad clowns, those are just driving me further away, and do fortify my disbelief.

"What decisions are we going to make EXACTLY? Stop driving cars?" - Modern

Yes. In part. Fuel prices will continue to rise, and you simply won't be able to avoid it.

More and more people will telecommute as a result.

You should ask yourself why you should maintain an economic system in which 80 percent of the workforce produces nothing but wasted effort through the production of products designed to fail, mindless accounting and paper pushing, etc.

"remember in observable geo-science warming causes CO2 with an 800 year lag, not the other way around." - StarTard

Warming caused by changes in the earths insolation on the other hand, slowly warms the ocean, and if the ocean's dissolved CO2 content was in near eqilibrium with the atmosphere, then it will out-gas some of that CO2.

The out-gassed CO2 will then produce greater warming of the atmosphere, which will in turn produce more ocean warming and more CO2 release.

It is this process that causes the the steep rise and overshoot in global temperatures at the end of each ice age.

Vendicar_Decarian: A rational thinker takes information where he/she finds it. Clearly from your comment above, you are neither rational or a thinker.

What's that suppose to mean? I don't want a musical to emotionally express the fear to influence me. That is propaganda 101. I'm rational because I require rational (non-emotional) evidence. I want some real evidence. I didn't get anything from that one. Comedians and sad clowns wasn't a parable, I meant it literally. In that regard, I don't understand your need to insult me. That is probably your only argument, as you also didn't provided any other. Maybe you've learned your math at Depeche Mode concert, but extraordinary claims require extraordinary evidence. I'm not willing to support an economical disaster based on heart-ripping strings in Gore's movie, or crying singers envisioning doom in a musical. If the insults are your only merchandize, than I stand uncorrected, and I will consider AGW still not to be proven.

OK, I get it. I don't need you to insult me here. I was naively expecting some arguments. You're probably thinking that it's a waste of time on me, but you're wrong, I was ready to change my mind (if any evidence - peer reviewed paper or anything was provided to me). Luckily, most of the world is happily ignoring AGW, and the changes are more or less cosmetic (emission trading) and the caravan goes on. The only preparations are for a GW in some areas where there will be actual impacts. You just assured me, that your arguments are empty. ;)

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PaulW; just a follow up, the deep ocean is generally stagnate (dark and cold) with some waters taking 1000's of years to circulate. The upper surfaces where diatoms, plankton and other organisms live is apparently very sensitive to PH levels, and the expect PH from Anthropogenic ocean acidification by 2100 is of really big concern. Reports suggest PH by 2100 could be 7.8. It will have a huge impact on the food chain. Add in the additional ocean temperature rise from Anthropogenic global warming of 10C by 2100 and you have a global disaster of catastrophic scales.

I'm sorry to burst your bubble Stargazer, but ocean acidification is a happening with horrific consequences to the bleached coral reefs. The shallower the water, and the warmer the water, the faster the acid eats away calcium including vital proto-planktons and diatoms.

You know, if you really read up on the subject, you would find that it doesn't take much in PH change to really upset the whole balance of an eco-system. Massive fish kills will be your fault.

You POS.

Sigh...

The peer reviewed research I linked shows MONTHLY pH fluctuations of GREATER THAN 0.127. Do you understand? NATURAL MONTHLY FLUCTUATIONS are GREATER THAN those CAGW alarmists claim will cause disaster. All the speculative nonsense about collapsing ecosystems IS FALSIFIED BY THIS OBSERVATION.

The fluctuations in the Oxygen and CO2 levels in your lungs are also greater than that needed to cause you significant breathing stress if you were exposed to the low levels of O2 and peak levels of CO2.

as proof that life is resilient to PH fluctuations in an attempt to suggest that ocean acidification (OA) doesn't matter. Star, your so focused on your argument that you missed the point. That paper is about monthly "fluctuations", not something steady state like is predicted with OA in 2100. By then it's a steady state PH of 7.8 and falling.

Anthropogenic Ocean Acidification could show up a lot sooner than 2100 given the way the ocean mixes. Regardless we are talking about effects on nearly half the food chain. That mister, is pretty severe!

totally moronic, co2 used to be much more prevalent in the past and life still existed in the oceans back then. It was called the carboniferous period and was 359 million years ago or so, where levels of co2 were at 800ppm, that is more than double that of back then. The oceans weren't dead and empty, and there were plenty of plants and animals too. This alone says to me that I shouldn't be paying to breathe and anybody here who thinks otherwise is a brainwashed dimwit.

stealthc; your comment is pretty moronic. Do you really want to tempt faith by letting Co2 levels reach 800ppm or more? It's bad enough we are hitting 400 with all of the global consequences to climate change. The floods, droughts, storm systems of a severity not seen in centuries, and global temperature rise with some of the hottest summers ever recorded. You living a land of fallacy if you don't see the connection to and exact correlation to, Co2 level rise in the atmosphere.

Anthropogenic Ocean Acidification is a major concern because it is changing so rapidily as the oceans absorb almost all of the Co2 we are sending into the air. As with the clown fish mentioned in the article, they are effected at a STEADY PH of 7.8 which is very possible for the oceans in 2100 at current excess Co2 level emission rates. Given all that science knows, do you really want to tempt faith by not restricting Co2 levels across the world? Or Cap CO2 globally to a safe level of emission?

"We need to get some broad based support,to capture the public's imagination...So we have to offer up scary scenarios,make simplified, dramatic statementsand make little mention of any doubts...Each of us has to decide what the right balanceis between being effective and being honest."- Prof. Stephen Schneider, Stanford Professor of Climatology,lead author of many IPCC reports